Hydraulic pump



I 1,629,141 y 1927' H. F.. BENSON HYDRAULI C PUMP Filed May 18. 192 2 Sheets-Sheet 1 awmmfoz W 7% i t M 5 H. F. BENSON mnmumc PUMP May 17, 1927.

Filed May 18. 1925 z sheota sheet 2 awuentod:

as, M awn/"@154 Patented May 1'1 191 37..

unirso STATES PATENT OFFICE.

I-IARR'Y F. BENSON, OF HOLYOKE, MASSACHUSETTS, ASSIGNOR TO WORTHING'ION PUMP AND MACHINERY GORPORATION OF NEW YORK, N. .Y., A CORPORATION OF VIRGINIA.

HYDRAULIC PUMI.

Application filed May 18,1925. Serial No. 30,899.

vunta es oi the invention more particularly appear when embodied in a multi-stage (it p- \voll pump.

'lhe invention relates more particularly to a certain novel construction of the various elements in con'il'iinat-ion, the rotary impelle -s, iliitusion members and intermediate pas-- f-ia s or chau'iljiers, for-mingtogether the (low pa Jap'osthroug h the pump, being; designed to present certain novel advantages in respoi-t to velocities and directions of flow and equalization ot water PlftFSSiP-PQ, and to cer tain novel 'ter'iturcs oi the eleunuits themselves icularly of the impeller and (lit? Fusion iucu'iliers, not only ada i itiup; thein' for their cooperative functions but securing cer-- tain novel advantages in their individual Fu ctions.

"'llilill object ct my invention is to pro high speed pump oi? large capacities and of high pressure head per stage with a relatively small diameter oi impeller and pumpwaking, thus adapting the pump par t cula ly to (leep well use.

Anotltr general object of the invention the production of such a pumphaving a h speed impeller of Wide range of efficiency and capacities without excessive variations require l in the driving power, thus enabling a reduction in the size and Weight of the pump out it; drive by relatively high speed motors under a fair approximation to con- .nt 'mxvor condi one throughout the range s aural" 1i ot the pump. ill illll U} i l zporzed on the initial stream i net head produced by rfiichod :ible. eific'iency'in pumps of the general type to which this invention relates, it is esecntial to avoid, all unnecessary energy losses .within the p ump passages, such as those due to ailinrii iit cliaiugcs in the velocity or directhe pump 1' s on oi the uuin i there must In order to attain the highest. poo

tion of tho flowing liquid Wl'llCllI'GSlllli in surface friction, the formation of eddy currents or unequal Water pressures in areas normal to the line of flow.

i'lccordingly, my invention contemplates, as one of its more particular objects, such construction or conformation, in cooperative plan or relation, o1 the various elements forming the how passage of the pump, as in the operation of the pump to produce the final head orpressure at theoutlet by impressingupon the inflowing stream the required changes in its initial velocity and direction gradually and along such lines of How as to reduce surface friction to a minimum, avoid eddy currents and, in tact, efi'ect equalization of Water pressures throughout areas normal to the line of flow.

M invention further particularly contem plates a novel impeller combining certain advantageous features-of the axial and the centrifugal types, this novel impeller being designed to receive the incoming liquid in substantially true axial direction and to im press thereon by gradual increments and along certain distinct lines of flow, a radial component With the radial component increasingly predominating toward the outlet of the impeller, the resultbeing a condition of true axial flow at the entrance and a combined axial and centrifugal action as the liquid passesthrough the impeller to the dis charge. The initial. axial flow has been found to be advantageous in the avoidance of eddy currents in the entering stream, shock of entrance and consequent loss of energy and; quantity flow. The gradual increase of the radial. component and centrifugal action hasbeen found to be particularly advantageous not only in the continued unbroken and smooth flow of the Water with out abrupt change in its velocity or direction "pressures throughout areas normal to the line of. flow ot" the liquid through the impeller, but also a. uniform increase of energy oi? flow irominlet to outlet on all radii 01' eddyless flow and the highest possible cabpacity and efliciency.

The invention further contemplates the provision, in association with the novel im-- peller, of a vaneless chamber passage for the immediate reception therein of the outflow from the impeller, with smooth surfaced 'alls of a form and contour enabling the water outflowing from the impeller to find its own path under the conditions as to velocity and direction of flow imposed there on by the impeller. without substantial in crease of surfaceittr-iction or formation of eddy currents. This chamber passage may, within the broader aspect-s of ny invention, take different forms and may be used with different types of diffusers for converting the velocity of the flow into pressure, as. for instance, a volute chamber through which the liquid isdelivered finally or to the next im ller. y invention more particularly contemplates, however, the employment of this chamber passage in association with a diffusing member on its delivery side. and with the chamber passage therefor between the impeller and the diffusing member, receiv ing the flow from the one and delivering it to the other. And for such use, the vaneless chamber passage is formed not only to receive the flow from the impeller without substantial change in direction and velocity of that flow but also to gradually change that flow from its axial radially outward direction imparted thereto by the impeller in angle at their inlet edges to the line of flow from the. chamber passage so as to receive the flow therefrom without change of direction. An important object of the diffusion member is to return the flow to true axial direction. either for final exit from thepump or for delivery to the next impeller of the series in themulti-stage .con-

struction of the pump. Preferably also,the

diffusion member is designed to effect. 'to some extent at least, a conversion of velocity into pressure, although this is not of primary importance in the functioning of that member. In harmony 'with the general plan of the various. elements forming the flow passage through the pump and affecting the velocities and directions offlow,the diffuser embodies certainfeatures of formand contour of the guiding vanes and. adjacent passage surfaces, gradually impressing upon the liquid those final changes in velocity and direction of flow which produce the axial outflow under the desired head, the lines of flow imparted to the liquid being such as to present a smooth, eddyless current of constant pressure and energy of flow throughout each successive plane normal to the line of flow.

The foregoing objects and principles of my invention as well as other objects and principles thereof, will more fully appear in the description hereinafter given of a concrete embodiment of the invention in its present preferred fornii- It is to be understood, however; that .inyinvention is not limited in its principles to such embodiment but that other embodiments and modifications of the present one may be made within the broad principles of the invention and as defined in the appended claims.

The concrete illustrative embodiment of the invention referred to is shown in the accompanying drawings forming a part of this specification.

In these drawings:

Fig. l is a view, partly in side elevation and partly in vertical longitudinal section, of a portion of the pump, from the drop pipe downwardly, the pump illustrated being of the multi-stage deep-well type. In this view the impeller blades are omitted from the sectional portion in order to show more clearly the inner contours of the inipeller core and shroud ring.

Fig. 2 is a transverse sectional view through the impeller and whirl chamber, on

the line of Fig. 1, looking in the direction of the arrows;

Fig. 3 is a perspective view of one of the impellerunits. the view being on a scale enlarged over that of Fig. 1;

Fig. lvis a plan view, on the same scale as F ig. .3, partly broken away, of the outlet face of the innecller unit, showing the delivery opening between the delivery end cdges of each two successive vanes and a portion of the water-contact surfaces of two I of those'vanes;

Fig. 5 is a plan view. on an enlarged scale, of the delivery face of the lower diffuse-r unit of Fig. 1,-bnt showing the outer casing or wall partly in section on the line 5-501- Fig. 1., looking in the direction of the a rows on that figure; and

Fig. 6 is a perspective view of the same 'unit with the outside casing or shell removed to show the form of the vanes.

The pump here shown for the purpose of more fully illustrating the broad principles of the invention, as well as.- prcsenting certain more detailed. features. found of value in practice, is of the deep-well two-stage type, having any suitable type of driving head, .not necessary here to be shown, coupled to the vertical impeller shaft 1.0

Ill

eeann which extends down through the drop pipe llnand through thesuccessive assembled units of the pump as shown in Fig. 1.

As already stated, the essential parts of the novel pump acting upon. the liquid to be delivered and impressing on that liquid from its initial state those characteristics of velocity and direction of flow required to insure the results aimed at by my invention, are in each of the pump stages. the impeller unit, the diffuser spaced therefrom and the intermediate chamber passage receiving the water in its whining movementof flow from the impeller and delivering that flow somewhat changed in direction to the diffuser.

The impeller units, two in number in the present illustrative pump, are indicated genorally by thennnrcral 12 on Fig. Lthe diffuser units by the numeral 13, and the intermediate chamber passages, which because of the cln'u'acteristic whirling flow of the ater tlun'ethrough, may ap ni-opriatcly be tern'led whirl chambers by the numeral 14. 'lnlet guide vanes 15 are preferably provided on, the entrance side of the lower impe'ler unit, to insure an initial true axial flow of the water to the impeller. The impcllprs 12 are mounted on the shaft 10 for rotation therewith while the dili users are fixed; as shown. their hubs serving as sup ports for the bearings 1.6 of the shaft.

The impellers, diffusers and whirl chambers of the two-stages of the pump are (inplicates so far as their essential parts pertaining to the invention are concerned and hence a description of one of each applies to the other of thepair. They are allshown in Figl in half section as cut by an axial plane passing through the center of the impeller shaft 10.

Viewed along thesection plane of Fig. l,

the impeller may be said to comprise a ecu-- lral cone-shaped core portion, a half section of which is there shown, having a hub "17 extending about and secured to the impeller shaft lO and a peripheral ring or shroudv l8, spaced from the core to provide the flow passage indicated by the arrow line of flow, that pass: e having the axially directed inlet 19 of greater dimensions measured in the section plane of Fig. 1, than the obliquely outward directed outlet 20. and having smooth) walls of large radii of curvature between the two. i The impeller blades or vanes are located in the passage thus gem-wally. dclined and in fact divide the passage into a plurality of passages. one between each two successive vanes. The cross-sections of any one such flow passage'takenon a plurality of axial planes intersecting the passage,-

would, if each such cross-section were swung to the axial plane in which the sectional view of .llig. l taken, and were projected there-- on, present however, the cl'iaracteristics just referred to, I V

The detailed characteristics of the impeller vanes and flow passages asembodied in the illustrative example of the novel impeller, and which example has been found in practice to constitute one very effective embodiment in attaining the objects and purposes of the invention, will more fully appear from a consideration of Figs. 2 to 4:, inclusive. V

Referring first to the perspective view of the impeller shown in Fig. 3, it is to be noted that the impeller vanes Qlstart at the inlet end 19 in a plane at right angles to the impeller shaft or axis of rotation of the impeller, their inlet edges extending in that plane from the hub of theimpeller in. diverging curves outwardly to the annular projecting shell forming the outer boundary of the inlet. These characteristics, and particularly the bringing of the inlet edges of the vanes inwardly to the impeller hub, provide large entrancecapacity with a minimum of diameter of the impeller and a true axial entering flow. i

As heretofore stated, an object of the invention, in the novel impeller, is to provide not only for a true axial entering flow but also for a superimposed centrifugal impeller action on the water flowing through the impeller to increase the lifting effect. ithout some provision to prevent it, however,

the superposition of a radial componentof flow with its attendant centrifugal action by the rapid rotation of the impeller, presents very substantial energy losses and reductions in outflow by reason of eddy currents de veloped by unequal pressure effects on the water entering near the impeller shaft-and that entering near the outer edges of the inlet openino'. Themeans which I have devised for avoidingthe disadvantages mentioned comprises a contour ofinipeller vane surfaces from inlet to outlet ends actingnpon thewater to gradually decrease the axial component of flow and gradually increase the radially outward component toward the impeller outlet. In the present illustrative embodiment of the invention, such means may be described a gradual warming of the vane surfaces of the impeller from a position where the entrance edges are in a plane normal to the axis at the entranreend to a position where the delivery edges are at an acute angle to any axial planeinten seating said-edges at the delivery endthe warping being such as to sec-urea uniform increase of energy throughout 'all arcasnormal to the flow. These vane characteristics are shown more particularly in Figs. 2 to il, inclusive. In the perspective view, Fig; 2),

as already mentioned, the impeller vanes 21,

at the inlet end, start with their edges in a plane normal to the impeller axis; From their inlet edges in the plane refer "id to, the vane surfaces proceed in sweeping flow lines gradually radially outward and axially toward the outlet end or face of the impeller and with a gradually increasing inclination or warp of the vane surfaces obliquely inward, in the direction of the outlet "lace, toward the axis of rotation, until, as shown in Figs. 3 and l, the outlet end edges of the vanes, indicated at 21, are presentedat oblique angles to the impeller axis as on a conical surface with the slope of the surface toward. the axis in the delivery direction and with the opposite terminai points ot each vane indicated lrythenumerals 22 and 23in Figs. and l, on dilteren-t. radii, with the advance considered in the direction of the pump discharge terminal point 23 closer to the axis than the rearward one The extent o'l' warpot the impeller vanesmay bevaried depending upon the size and;

rotational speed of the in'ipeller design of the delivery edges to an axial plane intersecting said edges, the a gm at the deliv my end being preferably smaller for so ll radial size pumps of high capacity. I have found in actual practice of the invention that an impeller having vanes (.(i'iittii'fiiiftg to the principles of surface uni-s iing l 2 referred to, impresses n on the enter ng flow such a gradual inc ward component. as to equalize pressure ett'ects on the Water eiiteriig near the i. peller shaft and that entei'ng near the outer edges of the inlet. opening, notwithstaiuling the contritugittfforce developed by the rapitlly rotating impeller, and to produce uniform increaseot. energy from inlet to outlet on all radii and "tl'ieretore with the energy unit'orm tl'iroughout each area or plane'normal to the flow.

@ther characteristics of the novel impel- 'ler additionally contribute to its capacity and efiiicieney, particularly for the small l v I V l-ugh speed impeller desired. In the prelerredembodiment of my novel impeller,

vthe inlet and outlet between each tV-(MSUU- eessive .vanes at their opposite ends sustain a definite. din'iensional relation to each other. The largest radius of the'jinlet is made to equal, approximately, the smallest radius of the outlet, this enabling the determination: of the least. maximum distance from the impeller axis of the inner and outer edges of ill).

istic is illustrated in Figno parison of Figs. 2 and The l 1li81"S[lI the vanes which will prod uee a: small pump capable of high speed and with maximnm capacity and lifting efl'ect. This characten andby a com ler axis to the inner surface of the inlet ring 19. And the smallest radius of outlet, such as outlet 27 shown in- Fig. 3, extends from the impeller axis to the inner or advanced tip of the outlet edge of the vane, indicated at 251, or, what amounts to the same thing, to the outer edge of the rap rim 24. In other words, the points 26 and 23, approximately or ally distant from the impeller axis, markthe terminals referred to oi those op 'iosite edge portions of each vane extending from inlet to outlet face of the impeller, their angular tilisl ilacement from each other about the impeller axis depending. of coure. on the degree and extent of ruiuature design for an inuaellerot that ir tirular diameter. 'Obviously the inner s of the inlet edge of the vanes are on the outer ("e of the impeller hub, as indirated at .8 in Figs. 2 and 3, and the displacement of the outer tip (Figs. 3 and 4) of the outlet edge oi the vane is determined by the extent (it warp of the wine surface from the inlet. end to the delivery'enddesired or required for the size'o'l the pump and its maximum elliciency under the prin- ('iplo' of warping the vanes already referred to. Between these terminals at the inlet and outlet edges of the vanes, the vane surlat-es are developed in smooth mveeping lines 'lrom inlet to outlet face of the impeller so sis-to provide the gradual warping from edges: nori-nal to the axis at inlet to edges inclined to the axis at the outlet, as already referred to. y I

It is also to he observed fromFig. 3 and a comparison of Figs. Q-and that the dif t'crence between maximum and minimum radii, at outlet is less than at inlet. dillerence is due to a reduction of the maximum diameter of delivery openings for the sn'ialler sized and high speed pumphere shown. This is not essential, however, and thellelivery openings would, of course, be u'iade larger for larger pumps of lower speed.

I have found in the actual use of an impeller conforming to the principles hereinaliove referred tot that not only are the flow 'fiow, having also, howeverQener-gy components in directions inwardly obliquet-oward the axis of rotation in the general direction of flow due to the warping of the vanes 21. The annular and vaneless whirl chamber 14, formed by the casing unit 29 surround- This proper.

ing the impeller and diffuser 13, and eX- tending from the-delivery end of the impeller to the entrance side of the diffuser, is shaped in its boundary water-contact sur faces to receive and continue the flow from the ii'rrfieller without substantial change in direction of flow until the water has advanced well along the chamber walls where, in theadvance half portion of the chamber, the walls are curved inwardly on a large arc of curvature to impress upon the flow a gradual cl'iange of direction from axial radially outward to axially radially inward.

This whirlv chamber l l may, if desired, be made of increasing transverse dimensions toward the outlet end so as to produce some conversion of velocity of flow into pressure, but this result is not required with my diffusely and in the preferred form of chamber shown no such result is secured; The main function of the chamber is to enable the water entering therein from the impeller 10 find its own path under the velocity and direction conditions imposed thereon by the impeller with a gradual change of the general. direction of flow from axially radially outward to axially radially inward, as diagramn'iatically indicated by the flow line 82 projected into the section plane on which Fig. l. is taken.

Just as thewhirl chamber is shaped to receive the flow from the impeller under the velocity and direction conditions imposed thereon by the impeller. so likewise the vanes o l the diffuser are shaped in theirinlet portions to lie in the line of flow from the Whirl chai'uber and to receive the continued whirling flow therefrom at the angle of flow finally impre'sedthereon by that chamber, thus presenting a smooth flow without abrupt changes in velocity or direction and avoiding all shock of ci'itrance into the diffuser.

The primary function of the diffuser is to return the flow to a true axial one for delivery into the next impeller of the series, or in the case of the last unit, to deliver the flow into the mitlet conduit or discharge cone 33 (Fig. 1) from the pump units ;\n additional function is the conversion of velocity head of whirl into cffecti've pressure head in the discharge although the difiiuser vanes are not themselves the essential elements in producing that result.

The change from awhirling flow advancing through the whirl. chamber from. the impeller to a true axial flow presents substantially the same problen'is of avoidance of energy los s and reductions in outflow by excessive surface friction and eddy currents developed by unequal waterp'ressures along areas normal to the line of flow. presented by the changes from true axial flow imposed by the impeller. and substantially the same general principles are employed in their solution although the mechanical details differ in some respects becai'ise of the differing specific tui'ictions of the diffuser and inipeller. i

Viewed along the section plane of big. l. the d ll'uscr may said to comprise a central cone portion 34. a half section only words the flow passage referred to is one between tWo surfaces of revolution with the Mess uniformly passage increasing in transverse area from the inlet to the outlet. It is this uniform increase between the opposing faces referred to, from inlet tooutlet. which affects what ever conversion occurs from velocity to pres-- sure in the flow through. the diffuser. The diil'iuscr vanes are located in the passage thus generally defined and in fact divide that passage into a plurality of passages, one between each two successive vanes. 91. section in the plane on which the view in Fig. l is taken throughany one such passage presents however the characteristics just referred to.

The detailed characteristics of the diffuser vanes as embodied in the illn, rated example of the novel diffuser, will more fully appear from a coi'isideration of Figs. 2. 5 and 6.

Referring first to the plan' view of the outlet face of the diffuser. shown in Fig. 5, the flanged face of the ring; portion 35 is indicated. by the numeral 38 and the central cone portion by the minimal 34. The diffuser vanes 40 start at the inlet end inelined to the pump axis and are brought to axial at the delivery end so that their outlet edges ll are in a plane at right angles to the axis, as also shown more particularly in Big. 6 which a perspective view of the diffuser with the outer ring portion 35 re moved so asto more clearly show the vane characteristics. In other words, as in the impeller. the di'lfuser vanes are warped from normal to the axis to an inclination thereto, the difference being in the direction of warp. In the impeller the vanes are Warped from a position where their entrance edges are in a. pldllQl'l()1lllfll to the axis at the inlet end to a position where their delivery edges are at au acute angle to any axial planeintersecting said delivery edges at the delivery end. while in the diffuser the vanes are Warped from a position, where their entrance edges slope in an opposite direction to the discharge edges of the impeller and also are at an acute angle to any axial planes intersecting said edges at the inlet to a posit-ion Where each delivery flow surface is in a plane parallel to the axial plane intersecting the delivery edge normal at the delivery end. And, broadly considered, it may be said that the warping characteristics in the two cases are complementary, because the functions of the impeller and dili'user are cone plementary, the inlet ends of the diffuser vanes receiving the flow delivered from the outlet ends of the impeller with but little change from the outwardly whirling form imparted thereto by the warping of the impeller vanes and the warping of the diffuser vanes returning the flow to its initial axial direction under the same 't'avorable condi tions, including eddyless current. equalizations of water pressures, and uniform head or pressure in the flow throughout the entire area of the outlet, obtained in the function ing of the impeller.

The cooperative relation. in their vane characteristics, of the impeller and diffuser, as well as the cooperating relation to both of the whirl chambers between them. is shown in Fig. 2. which figure, as previously stated, is a sectional view on the line 22 of Fig. 1, looking in the direction of the arrows on Fig. l. The portion shown on the right hand. side of F ig. 2. is taken, it is to be observed, on the lowermost part of the section line 2-2 of Fig. 1, just inside the entrance rim 19 of the impeller (see Fig. 3 for a perspective view of that entrance rim), and at the junction of that rim with the annular member or shroud 18 of the impeller. The portion of the ri hthand side of Fig. 2 is. therefore, in e ect a partial plan view of the entrance face of the impeller, minus the entrance rim. The left hand portion of the sectional view of Fig. 2. that on the upper part of the line 22 of Fig. 1, shows a partial end view of the inlet face of the diffuser, the opposite, or outlet face of the diffuser being shown in Fig. The inlet end edges of two impeller vanes 21 are shown in full, lines in Fig. 2 with the inlet mouth 25 of an impeller passage formed between them, and also in dotted lines the obliquely inclined end edges 21 of one of these impeller vanes at its outlet end in the outlet face of the impeller, which out-let face is. of course, hidden from view in Fig. '2. but is partially shown. in Fig. 4:.

Fig. 2 shows also. in partial end elevation and in sections along the section line 22 of Fig. 1, the outer casing wall 29. and the whirl chamber 14 formed on the interior thereof. Looking in the direction of.

the water-flow into the entrance of the impeller as in Fig. 2, the water entering the inlet 25 emerges past the outlet ends 21 of the impeller vanes in a whirling flow 1n thopump axis suilicieutly for ts by the diffuser thus ens .dil'l'us-cr of small (lliUilQlOl in axial line with of Fig. 2, shows the entrance ed' to of the diffuser vaues i0 ohhquely inch .d from the entrance rim 42 oi the annusir uter member or shroud 35 (see aiso Fig.5. 1) to the conical face of the core portion lcl; of the diffuser just in advance of the cured cutrance rim 43 (see Fig. l. as well as l lig. 2) of that conical surface. .rs shown in Fig. 1. and by a cou'i 'iarisou of the views of the impeller slmwn in Figs. 3 and, d with the view of the diffuser shown in 2- the inlet edges 40 of the diffuser vanes {til lie in a p'ane inclined to the pump a stantially the angle of inclinat: outlet edges 21 of the ili pt .er runes but in opposite direction of inclination. l as shown more particularly. entrance cud edges 1-0 of the diil are disposed in the line of whi (clockwise as the parts are viewed in from the whirl chamber l i. without any substantial. chun sre in velocities I directimis of flow. in other words, the inipcl'er forum and delivers the whirling (low, the whirl chamber receives it and in the onward moreulent of the whirl gradually iu-L'iiuc it from its initial ra .inlly outward direction towa d h J! 4" the use (H a u Fi the in'i 'ielfer.

'lhe ditiuser vanes "i are. in 'arpc-zfl. planes throughout their erlircrxlcut their entrance cdgeu ill i:,.-ir cd lo the .EMH toaxial cud terminals i in plants normal .to the axis shown in in-s. ."3 and 3. and conform to the principles of warped and smooth flow lines. licreiulu t'orc ll. to in descriliinu' the i'i-Uli cha .crisliis of he impeller. In the constructiim illus trated. the diffuser vanes t wnise rcs are not relied on to provide the iucrcas area of flow passage in successive plan... the line of flow required ocity of inlet flow to n let of the diffuser. the div. opposite wall surfaces of the core izicin and the shroud or ring member 3.? 5. 4 diii ue cr (see Fig. 1), as already stated. lzciun' I: on for the reduction in velocity tow outlet end and consequent COUNT-2TH. i locity into pressure. but it will be u udciwztowl that the construction may be such that this conversion is secured in suhstai'itial amount by the form of the vanes or by the divergence of the opposite side walls. a shown. or by both. The war-pi. o l the ii ser from axial at the outlet end alone; a no surface toward the inlet end in directions of noon; 14:11

eurvatiilre gradually increasing radially out-- Ward along that surface, to a disposal of their inlet ends each in a plane inclined to the ditl'user axis; doesqhowerer, perform in'ipmtant functions in addition to the presentation oil? the inlet ends of the vanes in the line of flow'from the whirl. chamber. luv-v portant results attained ar the uecoinn'rulation of the higher \eloeitlesotllow at the inlet end over the velocities of out'ilow and V the equalization of water pressures through inn; a moven'ient ol rotation about the pump out each successive area normal to the. line,

oi :tlow 't'ron'rinlet tooutlet thus insuring full capacity of flow without eddy currents, a n'iininunn of surface liriction and other energy losses and a constant energy output or pressure head thrmigrhout the entire area ot the outletsw' That I claim is p y y 1.. In a hydraulic pump, in comhinatimi, a casing, an in'lpeller therein 'l ori'ning and delivering the how in a direction the rt'lsultant of outward radial, tangential and axial com-- ponents, anmmular chamber extending from the impeller. outlet and providing" a vane-tree passage for said flow, saia. chamber having; a boundary water-contact surface impressing upon the flow advancing: tlurealongr a grad ually increasing inward radial component and a dilt'user on the discharge side of said passage in axial aliuement therewitln having vanes with their inlet ends lying substan tially in the line/ of flow discharging from said chamber anda surface contour gradually impressing on the flow advancing therealong toward the outlet end a gradually increasing zxial component. 7

2. In a hydraulic pump, in combinatiom a pinup casing, an impeller therein delivering: theistrcam in an advancing flow havaxis, an annular chamber extending;l rom the impeller outlet vand providing a vane- :l'ree passage for saidllow and a diiii'user on the discharge side of said passagi'c having;

. vanes extending about the pump axis from axial atl'hcir outlet; ends tolulct ends lying substantuilly in the line ol the advancing; rotational flow.

: In a hydraulic pump, in rmnhinatioin a pump casing an impeller, \anedree whirl chambe and vane-emuppcd di ll user in. seriesT ber and of ans'ur'facecontour from inlet to outlet ends producing an axial outflow.

--l:."lin a. hydraulic pump in combinatiom a pump casinpyfan impeller in said casing zulapicd.inform and deliver an axjially'advancing and radially outward whirling flow, a dili'uscr in axial line with, but spaced lronrsaid in'ipellu and inning;- vanes oil a surface contour from iuletto outlet end arranged to form dividing walls for How passages. u; ending spirally about the pump axis said vanes being warped to gradually force the flow inward and tangentially in opposition to the tangential component of, the whirl at the inlet end and axially at the outlet end and a reversing chamber between said impeller and (liti'user adapted to reverse theradial component oi said whirling flow from radially outward to radially inward. :7. in a hydraulic pump in combination, a pump casing an impeller and dill user therein spaced inaxial alinement, said impeller having vanes te urinating at (he delivery end on a peripheral surface of the impeller inclined toward the axis in the direction ot the dillnser and with the end edges of said vanes at an inclination to the radial, said dill'user having vanes terminating at their inlet-ends on a peripheral surface oi? the diffuser inclined toward the in thedireetion of the impeller and with the inlet end edges of said vanes inclined to the radial in a dircction opposite to the inclination of said impeller vanes and a vaneeliree chamber concentric with and between said impeller and dilluser and having a boundary flowcontact surface sprciulin,g radially outward from said ini-i poller outlet and. converging radially inward toward said dit'luser inlet;

- (5. in a hydraulic pump, in C(illlbllldhlOll animpeller having vanes withtheir inlet ends in axial planes and proceeding in curved lines gradually radially outward and axially toward the impeller outlet and at an incliiial'ion -or warp ot the vane surfaces from axial to inclined in directions producin; a combined axial and radiallyoutward :llow a dilif'user spaced il rom the impeller outlet and in axial alinemeut therewith and prorided with vanes having; their inlet ends in planesol inclination to the axis and proceeding in curvedlinesgradually radially inward and axially to axial planes at the dili'usiur outlet and a reversing chamber re iallytowa'rd theimp'eller outlet and at an" inclination or warp oi the vane surfaces from axial to inclined in directions producmg a combined axial and radially outward.

flow, a diff user spaced from the impeller out let and in axial alinement therewith and a vane-free chamber reviving the liow from said impeller axially and radially outward,

and delivering said how to said dilluser.

8. Av rotary impeller having a core, a shroud, and a plurality of vanes, the surfaces of each of which vanes, at intersection with a plane normal to the impeller axis at the inlet end of the impeller, form arcs extending from the core to the shroud, said vanes being arranged spirally between the core and shroud, and extending incurved lines gradually radially outward, tangentially, and axially toward the impeller outlet, the anes being warped gradually so that at the outlet I the vane ends lie substantially on the surface tending from the core to the shroud, said vanes bein arranged spirally between the core and road and extending in curved lines gradually radially outward, tangentiall y, and axially toward the impeller outlet, the

' vanes being warped gradually so that at the outlet the vane ends lie substantially on the surface of an imaginary cone frustum whose axis is coincident with the axis of rotation of the impeller, the slope of said frustum being inward toward the outlet end of the inipeller, each vane end, at the outlet, making an acute angle with an axial plane intersectinn such end.

10. A rotary impeller for hydraulic pumps having opposite inlet and outlet openings with boundaries of different radii, measured from the impeller axis, the largest radius of theinlet approximately equalling the smallest radius of the outlet. the flow passages between inlet and outlet being provided with vanes in axial planes to the hub on the inlet side and extending radially outward and ax ially forward toward the outlet in a direction of warp disposing the outlet ends of the vanes in non-axial 1planes.

est radius of the outlet and the difi'erenee between maximum and minimum radii at the outlet being less than at the inlet, the How passages between inlet and outlet being provided with vanes in axial planes to the hub on the inlet side and extending radially outward and axially forward toward the outlet in a direction of warp disposing the outlet ends of the vanes in non-axial planes.

12. A rotary impeller for hydraulic pumps having oppositely disposed inlet and outlet openings with annular boundaries of diflei'ent'iJ-adii, the largest radius of the inlet equalling approxin'iately the smallest radius of the outlet. the inlet extending inwardly to the impeller hub. the flow passages be tween inlet and outlet being provided with vanes in axial planes to the hub on the inlet side and extending radially outward and axially forward toward the outlet in a direc tion of warp disposing the outlet ends of the vanes in non-axial planes and with their outlet edges on a slope with the terminal point of least distance from the impeller axis in advance of that of greatest distance.

iii. In a hydraulic pump, a diffuser member comprising a cone-shaped core member. an outer annular shroud, and a plurality of vanes located in the space between the core and shroud, and extending spirally in said space so as to form spiral channels between said vanes, the vanes having their inlet ends lying substantially on the slant surface of an imaginary cone frustum whose axis is co incident with the longitudinz'il axis of the diffuser member, the slope of said frustum being inward in the direction of the pump inlet, each vane end at the inlet making" an acute angle with an axial plane intersecting such end. the guiding surfaces of each vane at the discharge end lying substantially in an axial plane, each vane being warped gracb ua 11y from its inlet end to its outlet end.

In testimony whereof, I have hereunto set my hand.

HARRY F. BENSON. 

